Abstract: The presence of dense deception jamming not only causes numerous false alarms but also raises the threshold of constant false alarm rate detector, which severely degrades the detection performance of airborne radar. To suppress the dense deception jamming, a moving target detection method based on data fitting is proposed. Firstly, a data basis matrix is constructed utilizing sample data adjacent to the cell under test, which is used to represent the test data in the form of least-square fitting. Simultaneously, an upper-bound constraint is adaptively calculated to protect target signals from being fitted. The proposed method can effectively suppress the dense deception jamming and significantly improve the moving target detection performance of airborne radar. The effectiveness of the proposed method is verified by the experimental results on measured radar data.